An [Na+ + K+]coupledl-glutamate transporter purified from rat brain is located in glial cell processes

摘要: Abstract Polyclonal antibodies were generated against the major polypeptide (73,000 mol. wt) present in a highly purified preparation of [Na + K ]coupled l -glutamate transporter from rat brain. These able to selectively immunoprecipitate 73,000 wt as well most transport activity—as assayed upon reconstitution—from crude detergent extracts brain membranes. The immunoreactivity various fractions obtained during purification procedure [Danbolt et al . (1990) Biochemistry 29 , 6734–6740] closely correlated with activity. Immunoblotting sodium dodecyl sulphate extract, separated by two-dimensional isoelectric focusing-sodium sulphate-polyacrylamide gel electrophoresis, showed that recognized one protein species only. Deglycosylation gave 10,000 reduction molecular mass, but no immunoreactivity. findings establish represents or subunit thereof. also recognize and activity plasma membranes rabbit, pig, cow, cat man. Using antibodies, immunocytochemical localization was studied at light electron microscopic levels central nervous system. In all regions examined (including cerebral cortex, caudatoputamen, corpus callosum, hippocampus, cerebellum, spinal cord) it found be located glial cells rather than neurons. particular, fine astrocytic processes strongly stained. Putative glutamatergic axon terminals appeared non-immunoreactive. uptake glutamate such (for which there is strong previous evidence) therefore may due subtype different demonstrated us.